Preheat the oven to 180°C (356°F).
In a bowl, mix protein powder, oat flour, and baking powder together.
In a separate bowl, beat eggs, Greek yogurt, and milk.
Combine the two mixtures and stir until well blended.
Pour the batter into a bread mold.
Bake in the preheated oven for 20–25 minutes.
Let it cool before serving.